Stamp collectors can pick up a pair of specially designed souvenir envelopes this weekend at an event to commemorate the 150th anniversary of the Arizona Organic Act, which created the Arizona Territory.

The event is scheduled from 10 a.m. to noon Sunday at the Postal History Foundation, 920 N. First Ave.

Each envelope available at the event bears a stamp from a Civil War battle (Antietam or New Orleans) and a photo of President Abraham Lincoln, and will be canceled with a special Arizona Territorial Station postmark.

The pair will cost $5, or $6 by mail.

The Arizona Organic Act was introduced by Ohio Rep. James H. Ashley on March 12, 1862, while Tucson was still part of the Confederacy and was occupied by Confederate troops under Capt. Sherod Hunter. The bill passed the House by a narrow vote on May 8, 1862, but it wasn't until February 1863 that Ohio Sen. Benjamin F. Wade pushed it through the Senate.

During the process, a clause naming Tucson capital of the new territory was deleted, likely at the recommendation of Union Gen. James H. Carleton, then military governor of the area. Lincoln signed the bill on Feb. 24, 1863, creating the Arizona Territory from the western half of the New Mexico Territory.

The chief lobbyist for the law was Charles Poston, now often referred to as the "Father of Arizona."

The main officers of the new territorial government were Gov. John N. Goodwin of Maine, Secretary Richard C. McCormick of New York, Chief Justice William F. Turner of Iowa, U.S. Marshal Milton B. Duffield of New York and Poston as superintendent of Indian affairs.

With the exception of Duffield and Poston, the group traveled from Washington, D.C., to Fort Leavenworth, near the Missouri River, and then traveled over the Santa Fe Trail to Santa Fe, arriving on Nov. 26, 1863. On Dec. 29, at a watering hole called Navajo Springs near Holbrook, Goodwin and the other officers took an oath of office and McCormick raised the American flag.

It wasn't until Jan. 22, 1864, that the officials arrived at the territory's first capital, Fort Whipple. Arizona would become a state in 1912.